The present invention relates generally to power converters. More particularly, this invention pertains to bidirectional power converters and wireless power transfer systems.
Designing circuits and laying out printed circuit boards is a time consuming and expensive process. Further, having multiple circuits and boards requires tracking multiple revisions of multiple circuits and printed circuit boards, which adds layers of complexity. However, in current power transfer circuit design techniques, circuit and board layouts are created for one specific purpose. Having multiple circuits and board layouts, each with multiple revisions is therefore heretofore unavoidable.
Wireless charging systems are limited by, inter alia, size, space, and transmitter/receiver orientation limitations. That is, wireless charging systems for batteries have wireless chargers, but the batteries directly physically contact the circuits of the device powered by the battery. The battery is not fully wireless which can be advantageous in wet or sterile environments. Further, wireless charging systems are currently limited by distance and/or orientation. That is, in some systems a transmitter coil must nearly be in contact with a receiver coil (e.g., laying a cell phone equipped with wireless charging capabilities on a wireless charging pad). In these systems, the Z directional differential between the transmitter coil and the receiver coil is therefore near zero while the X and Y directional variations are within a margin of error (e.g., the cell phone and its power receiving coil are within a specified diameter of a transmitting coil or antenna of the charging pad). In other systems, the Z directional differential between the transmitter coil and the receiver coil may be substantial, but the transmitter coil and the receiver coil must be located on the same axis (i.e., almost no variation in the X and Y directions between the coils and no variation in pitch). If the pitch or X-Y translation is not accurate, the transmitter may be damaged, requiring replacement of the transmitter circuit board. Thus, wireless charging systems that cannot compensate for variations in transmitter and receiver coil relative locations are difficult to manage and repair, and they are not practical for many uses in the field.